This invention pertains to unitary lightweight molded protective helmets, and particularly to such helmets having outer and inner apertured surfaces integrally molded together preferably by using a blow molding procedure.
Various designs of protective helmets such as for wear by cyclists have been developed and used in the past. For example, U.S. Pat. No. 3,551,911 to Holden discloses a protective helmet made from a unitary piece of flat flexible material such as vinyl foam, which is die cut and perforated and then formed and retained to the desired helmet shape by additional taped pieces. U.S. Pat. No. 3,934,271 and U.S. Pat. No. 3,992,722 to Rhee disclose a formed protective helmet having openings and formed of a resilient plastic foam material and covered by a tough surface coating fused thereon. U.S. Pat. 3,935,044 to Daly discloses a helmet which utilizes separately spaced inner and outer shells with the intervening cavity filled by a resilient plastic foam material. U.S. Pat. No. 4,279,038 to Bruckner el at discloses a head protector made of one-piece apertured foam material having a closed surface skin. U.S. Pat. No. 4,434,514 to Sundahl et al and U.S. Pat. No. 4,612,675 and U.S. Pat. No. 4,627,115 to Broersma disclose protective helmets made of a plastic outer skin with a liner of soft molded foamed plastic material and having ventilation slots provided therein.
Although these prior art helmets have been found useful, further improvements in protective helmets are needed to provide the wearer with a strong helmet which is lighter in weight and also exhibits improved ventilation and shock absorption characteristics.
A principal object of this invention is to provide an improved lightweight and high strength cyclist helmet.
Another object of the invention is to provide a protective helmet of unitary dual shell construction which is readily manufactured by blow molding techniques.